From the study guide "Enlighten me! The Great Gatsby": he is a guest at
Gatsby's party. While everyone else is caught up in the pursuit of
wealth, fame, and experiences, the owl-eyed man seems to be the only one
who "sees" the truth. He seems to represent the reader, in that he says
what the reader is feeling. He questions whether Gatsby is for real, or
just a facade. When Gatsby is killed, owl-eyes is the only former guest
that attends the funeral. He seems to have true compassion for Gatsby
and feels sorry for the man like the reader does by that point.